ramps and viaduct ##s so they could be built high over the existing junction lanes ; once traffic was transferred to the new structures the old lanes could simply be closed off and removed . little of the original interchange remained when the project was finished . to save time and money , innovative construction methods were employed : the original plans called for the segments of the long ramps and spans ( used to direct @ - @ connect roads ) to be made of steel , but because building with steel would interfere with heavy traffic flow during construction , cast @ - @ in @ - @ place segment ##al concrete was substituted in the plans . however , zach ##ry decided to use pre
ramps and viaducts so they could be built high over the existing junction lanes ; once traffic was transferred to the new structures the old lanes could simply be closed off and removed. little of the original interchange remained when the project was finished. to save time and money, innovative construction methods were employed : the original plans called for the segments of the long ramps and spans ( used to direct @ - @ connect roads ) to be made of steel, but because building with steel would interfere with heavy traffic flow during construction, cast @ - @ in @ - @ place segmental concrete was substituted in the plans. however, zachry decided to use pre